The present invention relates to a surgical instrument and methods of use, and in particular to a surgical instrument for, and methods of use in, arthroplasty procedures carried out on the knee joint.
A variety of knee arthroplasty procedures are known. Many involve the use or orthopaedic implants including partial knee procedures, in which only some of the distal part of the femur or proximal part of the tibia are replaced, or total knee procedures in which both the distal part of the femur and the proximal part of the tibia are replaced.
Knee arthroplasty surgical procedures often also involve the soft tissues of the knee joint such as the tendons and ligaments. One example is ligament balancing in which the ligaments around the knee joint are adjusted, often by cutting the individual strands of ligaments themselves and/or releasing their attachments points from the bone, in order to balance the forces exerted by the implant components on each other, or on remaining bone, when the knee joint has been partially or wholly replaced. The balance of the knee joint can be investigated with the leg in flexion and extension to see how the ligaments and knee joint interact over the full likely range of motion of the knee joint.
Ligament balancing is not easy to achieve and outcomes can depend on the skill, judgment and experience of the surgeon. Also, ligament balancing is not entirely reproducible and outcomes can vary depending on the specific anatomy or condition of any patient's joint.
Hence, a successful knee arthroplasty procedure can be dependent on the combination of balance and alignment of the prostheses.
It would therefore be beneficial to provide an instrument and/or surgical methods which can improve the reliability of assessment of ligament balance during a knee arthroplasty procedure and/or the making of cuts or re-cuts to the tibia or femur.